For inspector, do not generally expect a metrology professional, especially in this economy. But ask about uncertatinty. If they know that it is a mathematical description of errors of a given measurement, then that is good. If you get a deer in the headlights look then you may want to review others first. Maybe come back to them but review others first.
Do what dentists call a working interview. Give them a part and drawing and have them inspect.
Ask what standards they have been involved with and in what roles. ISO9001, TL-9000, ISO 14001, ISO/IEC 17025:2005, ISO/IEC 17020, or similar.
Hope this helps.